Validating the Restricted Focus Viewer: a study using eye-movement tracking

Investigation of cognitive processes and visual attention during problem-solving tasks is an important part of understanding human reasoning. Eyetracking technology has proven to have many benefits in revealing visual attention patterns. However, the high price of accurate eyetrackers and the difficulties associated with using them represent major obstacles to their wider application. Therefore, previous studies have sought to find alternatives to eyetracking. The Restricted Focus Viewer (RFV) brings a small part of an otherwise blurred display to the focus of visual attention: A user controls what part of the screen is in focus by using a computer mouse and explicitly selecting the area to be shown in focus. Recently, some studies have employed the RFV to investigate cognitive behavior of users, and some researchers have even enhanced the tool to study usability. We replicated a previous RFV-based study while also recording gaze data. We compared the attention allocation in time and space as reported by the RFV and an eyetracker. Further, we investigated the effects of RFV's display blurring on the visual attention allocation of 18 novice and expert programmers. Our results indicate that the data obtained from the two tools differ. Also, the RFV-blurring interferes with the strategies utilized by experts, and has an effect on fixation duration. However, task performance was preserved.